DESTIN — A shark spotted at Crab Island on Monday appears to be a scalloped hammerhead, which is an endangered species.

Terra Throgmorton, senior aquarist at the Gulfarium Marine Adventure Park, said she was envious when she saw the video.

"I was so impressed because it was so beautiful," said Throgmorton, who added that the highly migratory species normally travels in large schools in very deep water.

The video, which was widely shared on social media, was shot by Lauren Woodley, who moved to Fort Walton Beach with her husband Brandon in May.

She said they were out at Crab Island early Monday morning until the rain chased them under the Marler Bridge. When they came back out at about 9:50, they spotted a fin moving toward them.

"It wasn't moving like a dolphin, I was like, 'I don't know if it's a dolphin,' " Woodley recalled.

She pulled out her cellphone and started recording.

"Once we got close enough he kind of swam away and was like, 'I don't want anything to do with you guys,' " she said.

Throgmorton suggested two reasons the shark might have been on its own in such shallow water.

It might have been foraging for sting rays or fish in the shallower waters.

It might also have gone into shallow waters to give birth.

Throgmorton said scalloped hammerheads can reach about 11 feet and that the one in the video was "certainly full grown." She wasn't surprised that it swam away from the people it encountered at Crab Island. Even if it didn't see them immediately, it would have sensed their proximity.

"If the shark isn't looking for a lot of action, people would scare them away, especially if they're by themselves."